Fuel leak at carb bowl screw- Tec HS50

[creia]

Looking for help as to what is causing this and how to correct it...
The carb has a leak at the mixture adjustment screw on the bottom of the bowl. It is a VERY slow leak, more like a seepage, really. To be clear, it is NOT coming from the nut/gasket at the bottom of the float bowl. It is running down the shaft of the screw itself, apparently where the screw penetrates/passes through the bowl nut.
Background: The carb WAS recently removed (bowl was completely drained of fuel), for engine painting, however no individual carb parts were removed and no screws were removed or adjusted during the process. The carb did not leak before it was removed, however, it started to leak at the screw once it was reinstalled and the engine was "test ran" for a short while. Coincidence? Or is there some internal gasket/seal that may have dried out or shrunk after the fuel was removed?
Thanks for any help!

[/IMG]

 

[george3]

It should have a adjustment screw, a spring, a little washer, and a snug fitting o ring gasket. in that order.

 

[bigevilone2]

Looking for help as to what is causing this and how to correct it...
The carb has a leak at the mixture adjustment screw on the bottom of the bowl. It is a VERY slow leak, more like a seepage, really. To be clear, it is NOT coming from the nut/gasket at the bottom of the float bowl. It is running down the shaft of the screw itself, apparently where the screw penetrates/passes through the bowl nut.
Background: The carb WAS recently removed (bowl was completely drained of fuel), for engine painting, however no individual carb parts were removed and no screws were removed or adjusted during the process. The carb did not leak before it was removed, however, it started to leak at the screw once it was reinstalled and the engine was "test ran" for a short while. Coincidence? Or is there some internal gasket/seal that may have dried out or shrunk after the fuel was removed?
Thanks for any help!

[/IMG]

There is a washer and a "o" ring above the spring on the adjustment screw. You need a new "o" ring.

 

[jrzmac]

the "o" ring on the end is either missing or broke, or shot?

 

[creia]

Gentlemen,
Thank you ALL for your replies- it is appreciated.:thumbsup:
Can the "O" ring be purchased individually, or is it usually part of a rebuild "kit"? Is this something that a good lawn mower shop would typically carry in stock, or would it be an order item? (The engine is older, circa 1977) Any specific recommendations on where to purchase? It appears that the bowl nut does not need to be removed to replace the "O" ring, however the screw will be. I've never had to adjust this mixture screw before, and I have concerns about getting it to run right when I reinstall.:doah: Is there a "standard" number of turns out it should be at least as a starting point?
Sorry about all of the questions- I'm just beginning to learn about these old Tec flatheads.:wink:

 

[KustomKartKid]

any decent small engine/lawnmower shop will have it althought they will probably try to sell you a "kit" of some sort or main jet assembly because they can't make any money on a 10 cent o-ring......if he's the friendly type he may just give you one......

while you have it out be sure to check that the drilled passages are clear...especially the little tiny one which clogs easily...if you've got bad eyes you won't even see this hole.....use a piece of "tag wire" to clear it...

once you re-install it turn the jet all the way in until it just touches (don't crank on it or you'll damge the needle)...then back out 1-1/2 turns as a starting point.

 

[jrzmac]

this number is for a bag of those "o" rings. #630740. Outdoor Distributors - Lawn Mower Parts! most of the time all you need is the o ring, not the whole carb kit. it's a lot cheaper...

 

[jeep2003]

count how many turns to bottom it out from its current position then reinstall it the same way

 

[creia]

O.K. - Got it (thank you):biggrin:
Re: Fuel mixture screw adjustment-
Turning which way(s) richens or leans the mixture?
Does it take much of a turn to make a big difference? (e.g. 1/4 turn)
Also, what is the additional adjustment screw on the SIDE of the carb, and when does that need to be adjusted?
As I previously stated these old Tec flatheads are new to me, and I'm trying to learn....:wink:

 

[jrzmac]

click here http://www.allotment.org.uk/assets/rotovator/Tecumseh-Engine-Manual.pdf and go to page 20. this kinda shows you what to do also

 

[george3]

if you plan to be in this area I have an o ring kit and can fix it and adjust in a couple min.

 

[mmisterbungl]

O.K. - Got it (thank you):biggrin:
Re: Fuel mixture screw adjustment-
Turning which way(s) richens or leans the mixture?
Does it take much of a turn to make a big difference? (e.g. 1/4 turn)
Also, what is the additional adjustment screw on the SIDE of the carb, and when does that need to be adjusted?
As I previously stated these old Tec flatheads are new to me, and I'm trying to learn....:wink:

righty tighty lefty loosey....same applies for carbs. turning right will shut off more and more fuel flow....left opens it up for more fuel.

less fuel - lean
more fuel - rich

 

[creia]

My sincere appreciation to all of those that replied (including the PM I received)!:thumbsup:I believe that I (now) have a good enough understanding to make the necessary repairs. :laugh:
Special message to george3: Your offer is most kind and generous (and I'm not that far from you), however, it's high time my son and I learn how to do this ourselves, and it appears that this task would be within our (limited?) realms. If we screw it up,:scared: however, does your offer still stand? (There would be a very good lunch in it for you):wink:
Here is yet ANOTHER example of members helping other members- what an incredible educational tool this forum is!:drinkup:
Thanks again guys,
Michael